[PATCH v4 11/59] ntfs: ->d_compare() must not block

Al Viro
2026-01-08T07:36:49Z

... so don't use __getname() there. Switch it (and ntfs_d_hash(), while
we are at it) to kmalloc(PATH_MAX, GFP_NOWAIT). Yes, ntfs_d_hash()
almost certainly can do with smaller allocations, but let ntfs folks
deal with that - keep the allocation size as-is for now.

Stop abusing names_cachep in ntfs, period - various uses of that thing
in there have nothing to do with pathnames; just use k[mz]alloc() and
be done with that. For now let's keep sizes as-in, but AFAICS none of
the users actually want PATH_MAX.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/ntfs3/dir.c | 5 ++---
fs/ntfs3/fsntfs.c | 4 ++--
fs/ntfs3/inode.c | 13 ++++++-------
fs/ntfs3/namei.c | 17 ++++++++---------
fs/ntfs3/xattr.c | 5 ++---
5 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/fs/ntfs3/dir.c b/fs/ntfs3/dir.c
index b98e95d6b4d9..cf038d713f50 100644
--- a/fs/ntfs3/dir.c
+++ b/fs/ntfs3/dir.c
@@ -423,8 +423,7 @@ static int ntfs_readdir(struct file *file, struct dir_context *ctx)
if (!dir_emit_dots(file, ctx))
return 0;

- /* Allocate PATH_MAX bytes. */
- name = __getname();
+ name = kmalloc(PATH_MAX, GFP_KERNEL);
if (!name)
return -ENOMEM;

@@ -502,7 +501,7 @@ static int ntfs_readdir(struct file *file, struct dir_context *ctx)

out:

- __putname(name);
+ kfree(name);
put_indx_node(node);

if (err == 1) {
diff --git a/fs/ntfs3/fsntfs.c b/fs/ntfs3/fsntfs.c
index 5f138f715835..bd67ba7b5015 100644
--- a/fs/ntfs3/fsntfs.c
+++ b/fs/ntfs3/fsntfs.c
@@ -2627,7 +2627,7 @@ int ntfs_set_label(struct ntfs_sb_info *sbi, u8 *label, int len)
u32 uni_bytes;
struct ntfs_inode *ni = sbi->volume.ni;
/* Allocate PATH_MAX bytes. */
- struct cpu_str *uni = __getname();
+ struct cpu_str *uni = kmalloc(PATH_MAX, GFP_KERNEL);

if (!uni)
return -ENOMEM;
@@ -2671,6 +2671,6 @@ int ntfs_set_label(struct ntfs_sb_info *sbi, u8 *label, int len)
err = _ni_write_inode(&ni->vfs_inode, 0);

out:
- __putname(uni);
+ kfree(uni);
return err;
}
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 0a9ac5efeb67..edfb973e4e82 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1281,7 +1281,7 @@ int ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
fa |= FILE_ATTRIBUTE_READONLY;

/* Allocate PATH_MAX bytes. */
- new_de = kmem_cache_zalloc(names_cachep, GFP_KERNEL);
+ new_de = kzalloc(PATH_MAX, GFP_KERNEL);
if (!new_de) {
err = -ENOMEM;
goto out1;
@@ -1702,7 +1702,7 @@ int ntfs_create_inode(struct mnt_idmap *idmap, struct inode *dir,
ntfs_mark_rec_free(sbi, ino, false);

out2:
- __putname(new_de);
+ kfree(new_de);
kfree(rp);

out1:
@@ -1723,7 +1723,7 @@ int ntfs_link_inode(struct inode *inode, struct dentry *dentry)
struct NTFS_DE *de;

/* Allocate PATH_MAX bytes. */
- de = kmem_cache_zalloc(names_cachep, GFP_KERNEL);
+ de = kzalloc(PATH_MAX, GFP_KERNEL);
if (!de)
return -ENOMEM;

@@ -1737,7 +1737,7 @@ int ntfs_link_inode(struct inode *inode, struct dentry *dentry)

err = ni_add_name(ntfs_i(d_inode(dentry->d_parent)), ni, de);
out:
- __putname(de);
+ kfree(de);
return err;
}

@@ -1760,8 +1760,7 @@ int ntfs_unlink_inode(struct inode *dir, const struct dentry *dentry)
if (ntfs_is_meta_file(sbi, ni->mi.rno))
return -EINVAL;

- /* Allocate PATH_MAX bytes. */
- de = kmem_cache_zalloc(names_cachep, GFP_KERNEL);
+ de = kzalloc(PATH_MAX, GFP_KERNEL);
if (!de)
return -ENOMEM;

@@ -1797,7 +1796,7 @@ int ntfs_unlink_inode(struct inode *dir, const struct dentry *dentry)

out:
ni_unlock(ni);
- __putname(de);
+ kfree(de);
return err;
}

diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c
index 3b24ca02de61..b2af8f695e60 100644
--- a/fs/ntfs3/namei.c
+++ b/fs/ntfs3/namei.c
@@ -68,7 +68,7 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
u32 flags)
{
struct ntfs_inode *ni = ntfs_i(dir);
- struct cpu_str *uni = __getname();
+ struct cpu_str *uni = kmalloc(PATH_MAX, GFP_KERNEL);
struct inode *inode;
int err;

@@ -85,7 +85,7 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
inode = dir_search_u(dir, uni, NULL);
ni_unlock(ni);
}
- __putname(uni);
+ kfree(uni);
}

/*
@@ -303,8 +303,7 @@ static int ntfs_rename(struct mnt_idmap *idmap, struct inode *dir,
return err;
}

- /* Allocate PATH_MAX bytes. */
- de = __getname();
+ de = kmalloc(PATH_MAX, GFP_KERNEL);
if (!de)
return -ENOMEM;

@@ -349,7 +348,7 @@ static int ntfs_rename(struct mnt_idmap *idmap, struct inode *dir,
ni_unlock(ni);
ni_unlock(dir_ni);
out:
- __putname(de);
+ kfree(de);
return err;
}

@@ -407,7 +406,7 @@ static int ntfs_d_hash(const struct dentry *dentry, struct qstr *name)
/*
* Try slow way with current upcase table
*/
- uni = kmem_cache_alloc(names_cachep, GFP_NOWAIT);
+ uni = kmalloc(PATH_MAX, GFP_NOWAIT);
if (!uni)
return -ENOMEM;

@@ -429,7 +428,7 @@ static int ntfs_d_hash(const struct dentry *dentry, struct qstr *name)
err = 0;

out:
- kmem_cache_free(names_cachep, uni);
+ kfree(uni);
return err;
}

@@ -468,7 +467,7 @@ static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
* Try slow way with current upcase table
*/
sbi = dentry->d_sb->s_fs_info;
- uni1 = __getname();
+ uni1 = kmalloc(PATH_MAX, GFP_NOWAIT);
if (!uni1)
return -ENOMEM;

@@ -498,7 +497,7 @@ static int ntfs_d_compare(const struct dentry *dentry, unsigned int len1,
ret = !ntfs_cmp_names_cpu(uni1, uni2, sbi->upcase, false) ? 0 : 1;

out:
- __putname(uni1);
+ kfree(uni1);
return ret;
}

diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index c93df55e98d0..f3bb2c41c000 100644
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -556,8 +556,7 @@ struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
if (unlikely(is_bad_ni(ni)))
return ERR_PTR(-EINVAL);

- /* Allocate PATH_MAX bytes. */
- buf = __getname();
+ buf = kmalloc(PATH_MAX, GFP_KERNEL);
if (!buf)
return ERR_PTR(-ENOMEM);

@@ -588,7 +587,7 @@ struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
if (!IS_ERR(acl))
set_cached_acl(inode, type, acl);

- __putname(buf);
+ kfree(buf);

return acl;
}
--
2.47.3